CH 10: Muscular System

Overview of Muscle Tissue

The muscular system consists of specialized tissues responsible for movement, posture, and heat production. Muscle tissue is classified into three types: skeletal, cardiac, and smooth, each with unique characteristics and functions.

• Four Traits All Muscle Types Share: Excitability, contractility, extensibility, and elasticity.

• Skeletal Muscle: Voluntary, striated, attached to bones, responsible for body movement.

• Cardiac Muscle: Involuntary, striated, found only in the heart, responsible for pumping blood.

• Smooth Muscle: Involuntary, non-striated, found in walls of hollow organs, responsible for movements like peristalsis.

Muscle Structure and Function

• Antagonistic and Synergistic Muscles: Antagonists oppose movement; synergists assist movement.

• Muscle Arrangement: Muscles are composed of bundles of muscle fibers (cells), organized into fascicles.

• Filaments: Myofibrils contain actin (thin) and myosin (thick) filaments.

The Sliding Filament Model

The sliding filament model explains how muscles contract by the interaction of actin and myosin filaments within the sarcomere.

• Sarcomere: The functional unit of muscle contraction.

• Steps in Muscle Contraction:

  1. Excitation

  2. Excitation-contraction coupling

  3. Muscle contraction

  4. Muscle relaxation

• Role of Calcium: Calcium ions trigger contraction by binding to troponin, allowing myosin to bind to actin.

• ATP in Muscle Contraction: ATP is required for both contraction and relaxation.

Muscle Fiber Types and Training

• Slow-Twitch vs. Fast-Twitch Fibers: Slow-twitch fibers are fatigue-resistant and suited for endurance; fast-twitch fibers contract quickly and are suited for power.

• Muscle Fatigue: Occurs when muscles can no longer contract efficiently due to depletion of energy sources.

Key Terms

• Synergistic muscles, Antagonistic muscles, Sarcomere, Muscle fiber, Myofibril, Fascicle, Troponin, Tropomyosin, Actin, Myosin, Neuromuscular junction, Acetylcholine, Acetylcholinesterase, Motor unit, Muscle twitch, Summation, Tetanus, Oxygen debt, Aerobic exercise, Resistance exercise, DOMS, Isotonic contractions, Isometric contractions, Myoglobin

CH 11: Nervous System Fundamentals

Functions and Organization

The nervous system coordinates body activities through electrical and chemical signals. It is divided into the central nervous system (CNS) and peripheral nervous system (PNS).

• Primary Divisions: CNS (brain and spinal cord), PNS (nerves outside CNS).

• Neuroglia: Support cells including astrocytes, oligodendrocytes, microglia, and Schwann cells.

• Types of Neurons: Sensory (afferent), interneurons, motor (efferent).

Neuron Structure and Function

• Dendrites: Receive signals and transmit them to the cell body.

• Axons: Conduct impulses away from the cell body.

• Myelin Sheath: Insulates axons, increasing conduction speed.

• Schwann Cells: Form myelin in the PNS.

Electrical Signaling

• Ion Channels: Regulate movement of ions, crucial for action potentials.

• Sodium-Potassium Pump: Maintains resting membrane potential.

• Action Potential: Rapid change in membrane potential allowing signal transmission.

• Threshold: Minimum stimulus required to trigger an action potential.

• Summation: Integration of multiple signals to reach threshold.

Neurotransmitters and Disorders

• Neurotransmitters: Chemical messengers (e.g., acetylcholine, dopamine, serotonin, GABA, glutamate).

• Disorders: Multiple Sclerosis (MS), Myasthenia Gravis, Parkinson's, Alzheimer's.

• Neuronal Pools: Divergent and convergent arrangements for signal processing.

Key Terms

• Neurons, Neuroglia, Myelin sheath, Sensory neuron, Interneuron, Motor neuron, Dendrite, Axon, Resting potential, Action potential, Neurotransmitter, Synapse, EPSP

CH 12: Central Nervous System

Functional Arrangement and Protection

The CNS is responsible for integrating sensory information and coordinating responses. It is protected by the skull, vertebrae, meninges, and cerebrospinal fluid (CSF).

• Meninges: Dura mater, arachnoid mater, pia mater.

• CSF: Cushions and nourishes the brain and spinal cord.

• Blood-Brain Barrier: Protects the brain from harmful substances.

Brain Regions and Functions

• Cerebrum: Higher cognitive functions, voluntary movement.

• Cerebellum: Coordination and balance.

• Brainstem: Vital functions (medulla, pons, midbrain).

• Limbic System: Emotions and memory.

• Gray vs. White Matter: Gray matter contains neuron cell bodies; white matter contains myelinated axons.

Homeostasis and CNS Tracts

• Vital Functions: Body temperature, feeding, sleep/wakefulness.

• Association Areas: Speech, memory formation.

Key Terms

• CNS, PNS, Ganglia, Meninges, Dura mater, Pia mater, Arachnoid layer, Cerebrum, Cerebral cortex, White matter, Gray matter, Thalamus, Hypothalamus, Pons, Medulla, Limbic system, Hippocampus, Amygdala, Reticular activating system, Beta waves, Theta waves, Delta waves

CH 13: Peripheral Nervous System

Functions and Reflexes

The PNS connects the CNS to limbs and organs, facilitating sensory input and motor output. It includes cranial and spinal nerves, and is involved in reflex actions.

• Cranial Nerves: Twelve pairs, each with specific functions.

• Spinal Nerves: Connect the spinal cord to the body.

• Reflex Arc: Pathway mediating a reflex action.

• Basic Reflexes: Stretch, withdrawal, crossed-extension, cranial, Golgi tendon.

Sensory Receptors

• Types: Mechanoreceptors, thermoreceptors, nociceptors, photoreceptors.

• Receptive Field: Area monitored by a sensory neuron.

• Dermatome: Skin area supplied by a single spinal nerve.

Key Terms

• Somatic sensory, Visceral sensory, Somatic motor, Autonomic motor, Sympathetic, Parasympathetic, Cranial nerves, Spinal nerves, Trigeminal neuralgia, Sensory receptor adaptation, Mechanoreceptors, Thermoreceptors, Nociceptors, Photoreceptors, Merkel cell fibers, Meissner's corpuscles, Ruffini corpuscles, Pacinian corpuscles, Receptive field, Referred pain, Dermatome, Alpha-motor neurons, Gamma-motor neurons, Upper motor neurons, Lower motor neurons, Muscle spindles, Golgi tendon organs, Monosynaptic reflex, Polysynaptic reflex, Stretch reflex, Withdrawal reflex, Crossed-extension reflex, Gag reflex, Corneal blink reflex, Babinski sign, Plantar reflex, ALS

CH 14: Autonomic Nervous System

Functions and Divisions

The autonomic nervous system (ANS) regulates involuntary physiological functions. It is divided into the sympathetic and parasympathetic systems, each with distinct roles.

• Somatic vs. Autonomic: Somatic controls voluntary movements; autonomic controls involuntary functions.

• Sympathetic System: Prepares body for 'fight or flight' responses.

• Parasympathetic System: Promotes 'rest and digest' activities.

• Neurotransmitters: Acetylcholine, norepinephrine.

• Receptors: Adrenergic (alpha, beta) and cholinergic receptors.

Key Terms

• Visceral reflex arc, Preganglionic neuron, Sympathetic chain ganglia, Acetylcholine, Epinephrine/norepinephrine, Adrenergic receptors, Cholinergic receptors, Alpha-1, Alpha-2, Beta-1, Beta-2, Beta-3 receptors

CH 16: Endocrine System

Glands and Hormones

The endocrine system consists of glands that secrete hormones to regulate body functions. Hormones can be lipid-soluble or water-soluble, affecting target cells via specific mechanisms.

• Exocrine vs. Endocrine Glands: Exocrine secrete into ducts; endocrine secrete directly into blood.

• Hormone Mechanisms: Lipid-soluble hormones act on intracellular receptors; water-soluble hormones act on membrane receptors.

• Second Messenger System: Many water-soluble hormones use second messengers like cAMP.

• Feedback Mechanisms: Negative feedback maintains homeostasis; positive feedback amplifies responses.

Major Hormones and Functions

• Anterior Pituitary: GH, PRL, ACTH, FSH, LH, TSH

• Posterior Pituitary: ADH, oxytocin

• Thyroid: T3, T4, calcitonin

• Parathyroid: PTH

• Adrenal Cortex: Glucocorticoids, mineralocorticoids, androgens

• Adrenal Medulla: Epinephrine, norepinephrine

• Pancreas: Insulin, glucagon

• Other: Melatonin (pineal), thymosin (thymus), EPO (kidney)

Hormonal Disorders

• Diabetes Mellitus: Insulin deficiency or resistance.

• Graves' Disease: Hyperthyroidism.

• Cushing's Syndrome: Excess cortisol.

• Addison's Disease: Adrenal insufficiency.

Key Terms

• Endocrine gland, Exocrine gland, Hormone, Target cells, Lipid-soluble hormone, Water-soluble hormone, First messenger, Second messenger, Antagonist hormones, Positive feedback, Negative feedback, Pituitary, Hypothalamus, Neurosecretory cell, Releasing hormone, Growth hormone, Prolactin, Thyroid stimulating hormone, Adrenocorticotropic hormone, Follicle stimulating hormone, Luteinizing hormone, Antidiuretic hormone, Oxytocin, Thyroid gland, Calcitonin, Parafollicular cells, Parathyroid hormone, Adrenal cortex, Adrenal medulla, Glucocorticoids, Mineralocorticoids, Androgens, Estrogens, Aldosterone, Epinephrine, Norepinephrine, Addison's disease, Pancreatic islets, Insulin, Glucagon, Thymus, Thymosin, Pineal gland, Melatonin, EPO, Leptin

Tables

Comparison of Muscle Types

Major Brain Regions and Functions

Types of Neurotransmitters

Hormones and Their Functions

Equations

• Resting Membrane Potential: (approximate, based on potassium equilibrium)

• ATP Hydrolysis:

• Muscle Force: (Force = mass × acceleration)

Additional info: Academic context and expanded explanations have been added to ensure completeness and clarity for exam preparation.